Method for fitting fuses to firecrackers



Feb. 4, 1930. YAMAGlsHl 1,745,391

METHOD FOR FITTING FUSES T0 FIRECRACKERS Filed Dec. 9, 1927 mam Patented Feb. 4, 1936 HATSUTARO YAMAG-ISHI, OF TAII-IOKUSHI, TAIWAN, JAPAN METHOD FOR FITTING FUSES T0 FIRE-CRACKERS Application filed December 9, 1927. Serial No. 238,961.

This invention relates to fire-crackers, a special kind of fireworks devised simply to utter sharp sounds, and has for its object to provide means for attaching a fuse to the cracking member, which consists in placing a stick of fuse bestrided over the tops of a couple of cracker-tubes arranged upright and side by side, with the ends of the fuse-stick inserted respectively in the cracker-tubes and therein fitted, and in thereafter filling the cracker-tubes with a cementing substance, chiefly composed of plaster of Paris, to fix the fuse ends, and with gunpowder and a substance for packing.

According to the present invention, it is possible to manufacture fire-crackers in a simple and unharmful manner and to permit both of economy of firing members and of the firm attachment of the latter. F irecrackers according to the invention may not be miss-fired, nor remain unexploded when once fired. Further the sounds of explosion of the cracker will be considerably greater.

In the processes hitherto known to produce fire-crackers, it has been usual to first place in a paper tube, having thick walls and not wide end openings, a charge composed of a clay alone or the same mixed with fine sand, the said charge serving as bottom, and thereafter to fill the upper space with gun-powder and again with clay, the latter being used to pack up the bottom opening of the tube. To affix a fuse to the cracker, a narrow passage is drilled out from the top clay lid down to amidst the gunpowder so that the end of the fuse may reach the gunpowder and make con nections therewith. After the fuse has been inserted in the tube, the top portions of the tube are pressed inwards so as to firmly secure the fuse between the walls. It might be said however that the manner of operation as mentioned is rather reckless and almost exposed to danger, since if it happens that any impurities such as sand, etc. are present in the clay mixed therewith, they are qulte probable to cause an explosion. Furthermore when the fuse is introduced through the narrow passage, it often takes place that it cannot be forced to travel up to the gunpowder, or that though it remain broken short of the full passage, yet it is impossible to find out the reason why the working is unsuccessful.

Now it should be noted that these are the defects due to which many a commercial cracker have to be complained of for not taking fire, or remaining as blind-cracker. Generally speaking, the above manner of operation, hitherto known, is not at all efficient.

In the accompanying drawings:

Fig. 1 is an elevational view of a firecracker embodying the present invention, showing how a couple of cracker-tubes, constituting together the cracking member, is united by a single stick of fuse in a side-byside arrangement.

Fig. 2 is a plan view of a compound firecracker, consisting of a series of component crackers, each composed of a couple of cracker-tubes as illustrated in Fig. 1 placed in alignment, showing how the main fuses of several component crackers are laced up with independent fuse-strings, and

Fig. 3 is an enlarged elevational sectional view of the cracker-tubes shown in Fig. 1.

The fuse fitting method according to the invention first prefers an arrangement of component parts asillustrated in Fig. 1, in which a couple of cartridge-like paper tubes (1), (2) are arranged upright and side by side, a stick of fuse (3) being placed bestrided over the tops of the said tubes. To attach the fuse (3) both to the two tubes, the ends of the fuse-stick are inserted respectively into the top openings of the tubes and therein secured against removal by pieces of paper that are applied to cover the top openings. The fuse-stick so fitted assumes, in a normal position, a figure something like an inverted U, see Fig. 1. To fill the tubes with the charge, they are placed turned upside down so that the bottom openings may come upwards. Into the tubes is first introduced plaster of Paris alone or the same mixed with 9 such substances as clay, minute sand and what not, so as to form top layers (8), (8) that are to fix therein the greater parts of the fuse-stick ends, as shown in Fig. 3. Gunpowder of some peculiar nature suitable for tened, they may be removed with ease, and,

moreover, such moisture hardens the surfaces of the layers (8), (8) to a sufficient degree, thereby perfectly closing up the top openings of the tubes. It is apparent that in the above construction, a single stick of fuse combines with its ends a couple of cracker-tubes into a complete unit of cracking body.

-. As will be seen from the foregoing description, the process of manufacture according to the invention can be carried out with ease and quickness. The fuse is fitted firmly to the tubes that constitute together the cracking body of the cracker. The arrangement in which a couple of tubes containing the charge for explosion are combined by a single fuse-stick, allows of economy in the firing material. These features will be quite advantageous in the manufacture of fire-crackers.

To enhance the sound in exploding the cracker, it is necessary to make thick and rigid the portions of the walls of the crackertubes that surround the gunpowder chambers. To ensure such structure, it is proposed to use, for the walls, material which has been made of a number of sheets of paper laid over one on another. Care should also be taken that packing up of the openings at both ends of the tubes becompletely effected.

To this end, it has been found that plaster of Paris is best suited.

In the case of sale, the fire-cracker according to the invention may be handled in numher. To do this, a number of crackers, consisting of several couples of cracker-tubes,

are placed in series, with each two crackertubes constituting a couple laid in alignment, as illustrated in'Fig. 2. The connections between these cracker-tubes are set up by inde pendent fuse-strings (4:), (5) that are laced up with the main fuses attaching to the respective couples of cracker-tubes.

Having now particularly described the nature of this said invention and ascertained the manner in which it is performed I declare that what I claim is 1. A method for attaching a fuse to a firecracker, consisting in placing a stick of fuse crosswise over the tops of a couple of cracker-- tubes, with the ends of the said fuse-stick fitted respectively in the said cracker-tubes, and in thereafter filling the said crackertubes with plaster of Paris, gunpowder and HATSUTARO YAMAGISHI.

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